© 2016 General Electric Company. All rights reserved.182 | =GE Oil & GasIsolatorsAnother split range solution is achieved by means of an Intrinsic Safety Isolator for each loopas shown in Figure 86 on page 183. Several manufacturers supply suitable isolators designedfor use with HART ® output circuits. Using an IS Isolator allows up to three SVI II ESDs tooperate from a single 4 - 20 mA DCS output. Each isolator has a low compliance voltage inputrequirement and a high voltage output capacity.Up to three isolators can be connected in series to a single controller output and each of themcan drive a positioner. Isolators are used to provide compliance voltage and isolation even ininstallations not requiring intrinsic safety. Consult the manufacturer for detailed installationinstructions.The HART ® loop address of each device must be set to 1, 2, and 3 (or any non-zero values) toallow a HART® master to recognize each SVI II ESD when connected to all three devices on thesafe area side of the multiple isolators. Do not use 0 for any of the positioners. A 0 causesHART ® masters to stop searching for additional positioners.
